Research Question

What is the forecasted call count for traffic stops in Fairfax City, VA for the remainder of 2025?

Literature Review

Payares-Garcia et al. (2023) explored how emergency call patterns in urban areas can be predicted using a dynamic spatio-temporal model. They used ten years of weekly call data from Valencia, Spain, and included factors like distance to major landmarks and changes in call volume over time. Their model was able to highlight areas where calls were more likely to increase or decrease and provided reliable forecasts with built-in uncertainty estimates. This study shows how combining spatial and temporal patterns can improve forecasting, which closely relates to the method used in this project to predict traffic stop calls in Fairfax City.

Payares-Garcia, D., Platero, J., & Mateu, J. (2023). A Dynamic Spatio-Temporal Stochastic Modeling Approach of Emergency Calls in an Urban Context. Mathematics (Basel), 11(4), 1052-. https://doi.org/10.3390/math11041052

Data

This study uses 18 years of call-for-service data provided by the Fairfax City Police Department, covering the period from 2007 to 2024. The analysis focuses specifically on the Traffic Stop call type, which includes 114,445 individual records. The data was filtered to include only these incidents, and then aggregated by day to support trend analysis and forecasting.

Methods

To forecast future traffic stop calls, a univariate neural network model was developed using historical daily call counts as the input. This approach focuses on learning patterns and trends from past data to predict future activity. The model was trained using time series forecasting tools in R and was used to generate monthly predictions for the remainder of 2025.

Findings

July

The forecast for July predicts moderate traffic stop activity across Fairfax City. Spatial analysis shows hot spots clustering near Fairfax Circle and along Old Lee Highway, particularly near the Fairfax Shopping Center. The northern section of Chain Bridge Road also shows a high density of stops. In contrast, southern areas near Pickett Road and Fairfax Station Road consistently register lower traffic stop activity. Compared to later months, July exhibits a relatively even distribution of activity.

August

August shows a noticeable rise in predicted traffic stops, especially concentrated in central and northern Fairfax. Key hot spots appear along Chain Bridge Road and the intersection of University Drive and Main Street. The cluster around George Mason University stands out this month, with clustered markers indicating frequent stops in that vicinity. Cold spots remain in the southern neighborhoods, below Fairfax Boulevard. Compared to July, August has fewer stops in fewer, busier areas.

September

September forecasts a slight decline in overall call volume but with more focused activity. The densest hot spot remains near the intersection of Main Street and Pickett Road, with a new cluster forming east of Route 123. There is a noticeable cold spot in the southwestern section of the city, extending beyond Braddock Road. Compared to August, stops are more concentrated along Main Street and surrounding roads.

October

Traffic stop activity remains steady in October with a shift slightly eastward. Hot spots form along Fairfax Boulevard and Route 50, especially near Kamp Washington. There is a notable drop in activity near George Mason University compared to earlier months. Cold spots appear near Layton Hall Drive and in nearby residential streets. Compared to September, stops are more focused on the central part of the city.

November

November forecasts a noticeable drop in traffic stops. The primary hot spot remains near Old Lee Highway but is less intense than in prior months. Northern Fairfax, especially near Chain Bridge Road, sees less activity. Cold spots spread across more of the city during this month. Activity is more scattered, with fewer traffic stops. Compared to October, there is a clear reduction in both count and spatial density.

December

Traffic stops in December are at their lowest for the second half of the year. The main hot spot is located along Main Street, especially near University Drive and North Street. Although the intensity is lower than in previous months. There are no new hot spots, and the overall spread of activity is minimal. Cold spots are widespread across the city, with very few or no stops in areas like Blenheim Boulevard, Fairfax Villa, and the neighborhoods beyond Braddock Road. Compared to November and October, December has fewer hot spots and a larger number of cold spots, showing the lowest level of spatial activity across all months observed.